TIMED

Thermosphere • Ionosphere • Mesosphere • Energetics and Dynamics

Mission Profile

TIMED (Thermosphere Ionosphere Mesosphere Energetics and Dynamics) is a NASA satellite launched on 7 December 2001 aboard a Delta II to study the least-understood and least-explored region of Earth's upper atmosphere, the mesosphere and lower thermosphere/ionosphere (MLTI) between 60 and 180 km altitude. Its four instruments measure temperature, wind, and composition throughout this coupled region where the atmosphere transitions from being controlled by chemistry and dynamics to being controlled by solar and geomagnetic energy inputs. TIMED has observed how this atmospheric region responds to solar activity cycles and seasonal changes, providing more than two decades of continuous measurements from this critical but difficult-to-observe region. TIMED is among NASA's longest-serving Earth science satellites, with its extended dataset now spanning two complete solar cycles.